Many produce products are harvested and packed in the field into containers which are ultimately purchased by the end consumer. Examples of such produce items include, but are not limited to, tomatoes, berries, grapes, mushrooms, radishes and broccoli florets. Many of these produce items require substantial post-harvest cooling in order to enable shipping over long distances and to prolong shelf life.
In use, a grower's harvesting crew harvests produce items of the type previously discussed directly from the plant in the field into the container. The containers are then loaded into trays, which contain a specific number of individual containers and the trays, when filled, are loaded onto pallets. The most common pallet used in the produce industry is the forty by forty-eight inch (40'.times.48') wooden pallet, and the vast majority of produce handling, storage and shipping equipment is designed around pallets of this size.
After the pallets have been filled and loaded in the field, they are transported to shippers who perform a variety of post-harvest processes to enhance the marketability of the produce itself. For many types of produce, including berries, a significant packing evolution is the post-harvest cooling of the packed fruit. Indeed, berry shippers are often referred to as "coolers". The process of cooling berries typically includes injecting a stream of cooling air into one side of a tray and thence through the individual baskets and around the berries stored therein. As the air cools the berries, it picks up heat therefrom which is exhausted from apertures on the opposite side of the tray.
Packages for use by berry coolers have undergone a systematic process of evolution to improve the storing and cooling of the fruit while reducing packaging costs. While early berry packaging products included the use or folded wood or chipboard containers, a common package for the marketing of strawberries for instance, is a one pound vacuum formed plastic basket developed in conjunction with Michigan State University. This one piece package, hereinafter referred to for brevity as a "Michigan basket", includes a basket body formed with an integral hinged lid which, after the basket is filled with fruit, is folded over and locked in place with respect to the basket body. The lid is retained in position by means of a detent, which engages an edge flange of the basket body. Disposed at or near the substantially flat bottom of the basket body are a plurality of apertures, typically elongate slots, to provide air flow through the body of the packed fruit in the basket. This air flow continues through a similar series of apertures formed in the lid. In the case of the strawberry package, typically, eight (8) sixteen ounce (16 oz) baskets are loaded into a formed and folded corrugated cardboard tray.
The tray developed for use with the Michigan basket has one or more openings along either of its short ends to enable air flow through the tray. From the previous discussion on berry cooling, it will be appreciated that in the typically formed strawberry package system in current use, the two individual baskets within the tray which are immediately adjacent to the air intake apertures formed in the ends of the tray receive substantially more cooling from air inflow than do the two packages at the discharge end of the tray. To overcome this deficiency in air flow, berry coolers are currently required to utilize substantial amounts of cooling energy to ensure that fruit packed at the discharge side of the tray receives sufficient cooling to prolong its shelf life, while precluding the freezing of berries at the intake side of the tray.
The previously discussed problem is due to the fact that the one pound strawberry baskets and the tray which contains it were developed separately. Specifically, the design of the previously discussed one pound strawberry basket was finalized prior to the design of the tray which ultimately receives eight of these baskets therein. The previously discussed one pound strawberry containers in current use measure approximately four and three quarter inches by seven and one quarter inches (43/4'.times.71/4') and are three and one half inches (31/2') tall with the top secured. As a result, the commonly used eight basket tray measures approximately fifteen and one-half inches by nineteen and three quarters inches (151/2'.times.193/4'). This tray size is to some extent mandated by the size of the baskets it contains. While no great difficulty was likely encountered in forming a tray to fit a given number of the baskets, the area or "footprint" of the resultant tray was not given sufficient consideration in the design of the baskets. This has given rise to a significant inefficiency of packaging.
Because the current eight--one pound strawberry trays, and the baskets shipped therein are not fitted together properly, the package does not fully utilize the surface area of a forty by forty eight inch pallet, therefore shipping of those pallets is not optimized. Specifically, using current basket technology, a layer of strawberries comprises six (6) trays per layer on the pallet. With eight (8) one pound baskets per tray, this means that forty eight pounds of fruit can be packed per layer on a standard 40 inch by 48 inch pallet. Because there is no way with current use packages to completely fill the pallet with trays, a significant portion of the pallet remains unused. This of course forms a further inefficiency of shipping.
Another problem with current use plastic produce baskets is that they are usually formed with vertical stiffening ribs. This is done to maximize the resistance of the relatively thin basket to deformation. These ribs also provide salient intrusions into the body of the basket. Where a pulpy fruit, such as berries, are packed in the basket, handling shock to the packed fruit, combined with its own weight turns these intrusions into sites where significant bruising of the packed fruit occurs. This loss of fruit quality results in higher costs the shipper, transporter, retailer and consumer alike.
The previous discussion has centered on the specific case of the one pound whole strawberry container preferred by consumers. It should be noted, however, that while strawberries comprise the bulk of all U.S. berry consumption, other berry crops also enjoy a significant position in the marketplace. Each of these berry crops has, to a certain extent, given rise to preferred packaging embodiments therefor. By way of illustration but not limitation, while strawberries are typically sold in eight ounce or one pound containers, blueberries are typically sold by volume, specifically, consumers tend to prefer the one pint package of blueberries. Raspberries, on the other hand, are typically marketed in small five or six ounce trays.
The trays into which each of these differing types of berry baskets are ultimately installed have not been designed with a view to integrating them with other berry or indeed other produce crops. This presents a problem to the small-to-medium sized grocery establishment which may not order berries in multiple pallet lots but may prefer, for various reasons, to mix quantities of berries on one pallet. Because the trays used in the several aspects of the berry industry are not integrated one with another this capability is, at present, not realized. Accordingly, smaller lots of berries as commonly shipped to small-to-medium sized grocers must typically be sold at a premium cost in order to compensate the grower, shipper and transporter for the packing and shipping inefficiencies occasioned by the lack of packaging design cohesion.
Another problem with the previously discussed Michigan basket is the latch which retains the lid in the closed position with respect to the body. The Michigan basket uses a single detent formed in the lip of the lid to engage the edge of the basket body lip. This latch arrangement has proven troublesome in that it is difficult to quickly and securely close in the field while being prone to unwanted opening during packing, shipping and while on the grocer's shelves.
Other workers in the packaging arts have attempted to solve the previously discussed latch deficiencies by means of forming snap fasteners in the edge material of the plastic baskets which they produce. The results obtained by this design are mixed. While the snap fasteners may be slightly more secure than the previously discussed edge latch, they are at least as difficult to align properly by pickers in the field as the Michigan basket latch.
The trays currently available for use with Michigan baskets designed for one pound strawberry packing are not generally well suited for the baskets in that the baskets are allowed considerable freedom of movement within the trays. This results in an increased incidence of shifting of the baskets within the trays, which causes an increase in bruising of the fruit stored in the baskets.
The final problem not contemplated by the prior art is that different quantities, types, and external forms of produce a require different cooling air flow regimes. Some combinations of fruit types and quantities benefit from the relatively laminar flow provided by the invention of U.S. patent application Ser. No. 08/591,000. Further research has shown that some combinations of produce quantity and type benefit from a relatively turbulent air flow through the basket during the cooling process.
What is clearly needed is an improved berry packing system which will significantly reduce the cooling time and cooling expense for the fruit contained in the baskets. To make such an improved system feasible, it must interface with commonly used and preferred materials handling apparatus, specifically the previously discussed forty by forty eight inch pallets in current use in the grocery industry.
The baskets of such a system should be capable of being formed in the preferred size or quantity configuration preferred by the end consumer, while simultaneously maximizing their footprint on existing pallet technology. The baskets should be formed to minimize bruising and other damage to the fruit packed therein. Furthermore, such a system should provide for the mixing of lots of different types, quantities and sizes of produce on a single pallet without substantial losses of packaging efficiency occasioned by differing types of misaligned trays.
The basket should possess a lid latch capable of being quickly and securely fastened in the field. The same lid should be capable of being repeatedly opened and closed during packing, while on the grocer's shelves and ultimately by the end consumer.
The packaging system should enable the packaging of one layer, or a plurality of layers of filled baskets therein.
Finally, the several components of the packaging system should be capable of providing cooling air flow regimes relatively optimal for the type and quantity of produce to be stored in the baskets.
If possible, the system should be formed utilizing existing equipment and machinery from materials of the same or lesser cost than currently available fruit packages.